LED-based luminaires have become increasingly popular of late due to the development of high lumen output LEDs that operate at low power. While such luminaires save energy costs, some of the electrical power supplied to the LEDs is converted into heat that may require dissipation to prolong the usable lives of the LED devices. Further, heat is typically developed by other elements, such as one or more driver circuits that develop power of an appropriate magnitude for the LEDs. Inasmuch as the heat developed by the LEDs is directed opposite to the direction the light is emitted, heat dissipation devices are typically disposed in thermal contact with a circuit board on which the LEDs are mounted. In other designs the thermal dissipation device may include the circuit board itself (with or without a heat exchanger in thermal contact therewith), in which case the circuit board may be made of a thermally conductive material, such as metal (aluminum, copper, one or more alloys) and/or a metal and composite material and/or a combination of thermally conductive and non-thermally conductive materials (for example, an alumina substrate with one or more flex connectors).
Still further, other non-heat producing circuit components may be packaged on the same circuit board as the LEDs and the driver circuit(s). The other non-heat producing circuit components include power connection terminals, one or more surge protection devices, a rectification circuit, and the like. Packaging all of the circuit components together results in a modular, all-in-one design that simplifies the process of designing the electrical and mechanical components of the luminaire. The modular design results in some duplication of components when multiple modular packages are used in a luminaire. Further, disposing all of the non-heat producing circuit components on the circuit boards together with the heat producing circuit components results in a relatively large combined size of heat dissipating circuit board being necessary, again, particularly in luminaires employing multiple modular packages, which contributes to cost.
A luminaire as described above may further require the capability of operating on different input voltages, such 120 volts or 240 volts RMS. While circuit designs are known that permit such operation (such as a switched mode power supply circuit that uses a buck regulator, a boost regulator, a buck-boost regulator, etc.), such designs are complex and relatively expensive.